Arterial Vasoregulation by Notch Signaling

项目摘要/摘要 血管平滑肌(SM)和内皮细胞(EC)协调控制动脉的分子信号 血管反应性。收缩和松弛信号的平衡建立血管张力，并直接影响 健康和疾病中的全身血压。我们的实验室发现了新的和矛盾的角色 血管壁上影响动脉功能的缺口信号。具体地说，SM Notch受体由 SM Jagged1配体促进肌球蛋白轻链激酶表达及钙敏感性诱导 肌球蛋白轻链(MLC)磷酸化，力量产生的分子标志。缺乏SM的小鼠 Jagged1的特点是血压和升压反应失调，动脉显示力量受损 一代。相反，EC DLL4配体刺激肌球蛋白的调节亚单位SM MYPT1的表达 磷酸酶(MP)，有利于MLC的去磷酸化和松弛表型。此外，EC DLL4缺乏 动脉以一种新的非独立方式产生血管松弛缺陷。总而言之，这些发现强调了 通过异型(EC-SM)和同型(SM-SM)细胞相互作用的指令Notch信号 并为血管调节的分子决定因素提供了新的知识。年的总体目标是 这一新的项目提案是定义生理上相关的Notch配体/受体，它调节不同的 动脉功能。在目标1中，我们确定了SM和EC Jagged1配体和Notch1的贡献 受体对血管健康和疾病动物的收缩和血流动力学反应的调节 模特们。目的2阐明血管内皮细胞DLL4配体在动脉中的生理作用和机制 放松一下。最后，Aim 3研究了Notch信号依赖的肌球蛋白调控的分子基础 通过钙敏化和/或脱敏的磷酸酶活性。实验方法包括完整的 体内、体外和体外血管分析的光谱，以了解相关的生理学和 Notch通路组件调节动脉功能的新分子机制。

PROJECT SUMMARY/ABSTRACT Vascular smooth muscle (SM) and endothelial cells (EC) coordinate the molecular signals governing arterial vasoreactivity. The balance of constrictor and relaxant signals establishes vessel tone and directly influences systemic blood pressure in health and disease. Our laboratory has uncovered novel and paradoxical roles for Notch signaling in the vessel wall that influence arterial function. Specifically, SM Notch receptors triggered by SM Jagged1 ligand promote myosin light chain kinase (MLCK) expression and Ca2+ sensitization inducing myosin light chain (MLC) phosphorylation, the molecular signature of force production. Mice lacking SM Jagged1 feature dysregulated blood pressure and pressor responses and arteries exhibit impaired force generation. In contrast, EC Dll4 ligand stimulates expression of SM MYPT1, the regulatory subunit of myosin phosphatase (MP), favoring dephosphorylation of MLC and a relaxant phenotype. Moreover, EC Dll4-deficient arteries yield vasorelaxation deficits in a novel NO-independent manner. Together, these findings underscore instructional Notch signaling through heterotypic (EC-SM) and homotypic (SM-SM) cell interactions in the vessel wall and provide new knowledge in the molecular determinants of vasoregulation. The overall goal in this new project proposal is to define the physiologically relevant Notch ligand/receptor that modulates distinct arterial functions. In Aim 1, we determine the contribution of both SM and EC Jagged1 ligand and Notch1 receptor in regulation of constrictor and hemodynamic responses in vascular health and disease animal models. Aim 2 delineates the physiological role and mechanism of EC Dll4 ligand in mediating arterial relaxation. Finally, Aim 3 examines the molecular basis for Notch signaling-dependent control of myosin phosphatase activity via Ca2+ sensitization and/or desensitization. Experimental approaches include a full spectrum of in vivo, ex vivo and in vitro vascular analyses necessary for understanding relevant physiology and novel molecular mechanisms through which Notch pathway components regulate arterial function.